This invention relates to wound suction evacuators, and more particularly, to the type of wound suction evacuators that are self-contained and independently operable for the removal of fluid from the human body and the like.
In many surgical procedures, and occasionally as a result of traumatic injury, it is desirable to withdraw body fluids from the wound site to promote healing and prevent complications. Evacuator systems comprising a flexible container to create a vacuum have been used in the drainage of these fluids.
One such prior art container is described in U.S. Pat. No. 3,115,138 to McElvenney et al. The evacuator of the McElvenney et al patent utilizes a self-contained compressible fluid-tight container. In the McElvenney container, a plurality of springs are disposed between the top and bottom. The container and springs are compressed and subsequently released to permit expansion. The expansion of the sealed container develops a vacuum which can be applied through suitable wound drainage tubing connected to the container for the evacuation of fluids. The tubing is connected to the evacuator through a valve opening which provides communication between the interior of the evacuator and the drainage tubing. The other end of the suitable tubing is laid within the wound of a patient for post-operative drainage of the wound.
Other examples of prior art wound evacuator devices are described in the following U.S. Pat. Nos. 3,376,868; 3,742,952; 3,774,611; 3,779,243; 3,809,086; and 4,141,361.
Wound evacuators typically are sold in an expanded state which is bulky and cumbersome for shipping or storing. However, some devices are capable of being mechanically retained in their compressed state, although their resilient force exerting or tensioning member is typically activated when in such a compressed state. For example, European Patent Application EP No. 0 048 164 A to Blake, et al. includes a large spring disposed between its top and bottom surfaces. This evacuator is compressed, whereupon a mechanical means may be utilized to latch the evacuator in this position until ready for use. Therefore, this evacuator can be shipped in a flat position and remain in this position until ready for use. But this structural arrangement requires that the spring member be compressed into its activated state while in this flat position, subject to fatique and/or accidential release.
Another evacuator device is described in U.S. Pat. No. 4,460,354 to Weilbacher et al. This device also has the capability of being retained in its compressed, also referred to as activated, position. This is accomplished by a valve mechanism which seals off the evacuator to prevent loss of the vacuum that is being generated inside the evacuator. This valve allows the evacuator to be sealed off in a number of positions, including the fully compressed position. The resilient tensioning means, typically an elastomeric band, is maintained in its stretched, activated position during compression.